src/getloadavg.c

   1 /* Get the system load averages.
   2    Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93, 1994, 1995, 1997
   3         Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  18    USA.  */
  19
  20 /* Compile-time symbols that this file uses:
  21
  22    FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
  23    KERNEL_FILE                  Pathname of the kernel to nlist.
  24    LDAV_CVT()                   Scale the load average from the kernel.
  25                                 Returns a double.
  26    LDAV_SYMBOL                  Name of kernel symbol giving load average.
  27    LOAD_AVE_TYPE                Type of the load average array in the kernel.
  28                                 Must be defined unless one of
  29                                 apollo, DGUX, NeXT, or UMAX is defined;
  30                                 otherwise, no load average is available.
  31    NLIST_STRUCT                 Include nlist.h, not a.out.h, and
  32                                 the nlist n_name element is a pointer,
  33                                 not an array.
  34    NLIST_NAME_UNION             struct nlist has an n_un member, not n_name.
  35    LINUX_LDAV_FILE              [__linux__]: File containing load averages.
  36
  37    Specific system predefines this file uses, aside from setting
  38    default values if not emacs:
  39
  40    apollo
  41    BSD                          Real BSD, not just BSD-like.
  42    convex
  43    DGUX
  44    eunice                       UNIX emulator under VMS.
  45    hpux
  46    __MSDOS__                    No-op for MSDOS.
  47    NeXT
  48    sgi
  49    sequent                      Sequent Dynix 3.x.x (BSD)
  50    _SEQUENT_                    Sequent DYNIX/ptx 1.x.x (SYSV)
  51    sony_news                    NEWS-OS (works at least for 4.1C)
  52    UMAX
  53    UMAX4_3
  54    VMS
  55    WINDOWS32                    No-op for Windows95/NT.
  56    __linux__                    Linux: assumes /proc filesystem mounted.
  57                                 Support from Michael K. Johnson.
  58    __NetBSD__                   NetBSD: assumes /kern filesystem mounted.
  59
  60    In addition, to avoid nesting many #ifdefs, we internally set
  61    LDAV_DONE to indicate that the load average has been computed.
  62
  63    We also #define LDAV_PRIVILEGED if a program will require
  64    special installation to be able to call getloadavg.  */
  65
  66 /* This should always be first.  */
  67 #ifdef HAVE_CONFIG_H
  68 # include <config.h>
  69 #endif
  70
  71 #include <sys/types.h>
  72
  73 /* Both the Emacs and non-Emacs sections want this.  Some
  74    configuration files' definitions for the LOAD_AVE_CVT macro (like
  75    sparc.h's) use macros like FSCALE, defined here.  */
  76 #ifdef unix
  77 # include <sys/param.h>
  78 #endif
  79
  80
  81 /* Exclude all the code except the test program at the end
  82    if the system has its own `getloadavg' function.
  83
  84    The declaration of `errno' is needed by the test program
  85    as well as the function itself, so it comes first.  */
  86
  87 #include <errno.h>
  88
  89 #ifndef errno
  90 extern int errno;
  91 #endif
  92
  93 #ifndef HAVE_GETLOADAVG
  94
  95
  96 /* The existing Emacs configuration files define a macro called
  97    LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
  98    returns the load average multiplied by 100.  What we actually want
  99    is a macro called LDAV_CVT, which returns the load average as an
 100    unmultiplied double.
 101
 102    For backwards compatibility, we'll define LDAV_CVT in terms of
 103    LOAD_AVE_CVT, but future machine config files should just define
 104    LDAV_CVT directly.  */
 105
 106 # if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
 107 #  define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0)
 108 # endif
 109
 110 # if !defined (BSD) && defined (ultrix)
 111 /* Ultrix behaves like BSD on Vaxen.  */
 112 #  define BSD
 113 # endif
 114
 115 # ifdef NeXT
 116 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 117    conflicts with the definition understood in this file, that this
 118    really is BSD. */
 119 #  undef BSD
 120
 121 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 122    defined to mean that the nlist method should be used, which is not true.  */
 123 #  undef FSCALE
 124 # endif
 125
 126 /* Set values that are different from the defaults, which are
 127    set a little farther down with #ifndef.  */
 128
 129
 130 /* Some shorthands.  */
 131
 132 # if defined (HPUX) && !defined (hpux)
 133 #  define hpux
 134 # endif
 135
 136 # if defined (__hpux) && !defined (hpux)
 137 #  define hpux
 138 # endif
 139
 140 # if defined (__sun) && !defined (sun)
 141 #  define sun
 142 # endif
 143
 144 # if defined(hp300) && !defined(hpux)
 145 #  define MORE_BSD
 146 # endif
 147
 148 # if defined(ultrix) && defined(mips)
 149 #  define decstation
 150 # endif
 151
 152 # if defined (__SVR4) && !defined (SVR4)
 153 #  define SVR4
 154 # endif
 155
 156 # if (defined(sun) && defined(SVR4)) || defined (SOLARIS2)
 157 #  define SUNOS_5
 158 # endif
 159
 160 # if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 161 #  define OSF_ALPHA
 162 #  include <sys/mbuf.h>
 163 #  include <sys/socket.h>
 164 #  include <net/route.h>
 165 #  include <sys/table.h>
 166 # endif
 167
 168 # if defined (__osf__) && (defined (mips) || defined (__mips__))
 169 #  define OSF_MIPS
 170 #  include <sys/table.h>
 171 # endif
 172
 173 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 174    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 175    that with a couple of other things and we'll have a unique match.  */
 176 # if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 177 #  define tek4300                       /* Define by emacs, but not by other users.  */
 178 # endif
 179
 180
 181 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 182 # ifndef LOAD_AVE_TYPE
 183
 184 #  ifdef MORE_BSD
 185 #   define LOAD_AVE_TYPE long
 186 #  endif
 187
 188 #  ifdef sun
 189 #   define LOAD_AVE_TYPE long
 190 #  endif
 191
 192 #  ifdef decstation
 193 #   define LOAD_AVE_TYPE long
 194 #  endif
 195
 196 #  ifdef _SEQUENT_
 197 #   define LOAD_AVE_TYPE long
 198 #  endif
 199
 200 #  ifdef sgi
 201 #   define LOAD_AVE_TYPE long
 202 #  endif
 203
 204 #  ifdef SVR4
 205 #   define LOAD_AVE_TYPE long
 206 #  endif
 207
 208 #  ifdef sony_news
 209 #   define LOAD_AVE_TYPE long
 210 #  endif
 211
 212 #  ifdef sequent
 213 #   define LOAD_AVE_TYPE long
 214 #  endif
 215
 216 #  ifdef OSF_ALPHA
 217 #   define LOAD_AVE_TYPE long
 218 #  endif
 219
 220 #  if defined (ardent) && defined (titan)
 221 #   define LOAD_AVE_TYPE long
 222 #  endif
 223
 224 #  ifdef tek4300
 225 #   define LOAD_AVE_TYPE long
 226 #  endif
 227
 228 #  if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 229 #   define LOAD_AVE_TYPE long
 230 #  endif
 231
 232 #  ifdef _AIX
 233 #   define LOAD_AVE_TYPE long
 234 #  endif
 235
 236 #  ifdef convex
 237 #   define LOAD_AVE_TYPE double
 238 #   ifndef LDAV_CVT
 239 #    define LDAV_CVT(n) (n)
 240 #   endif
 241 #  endif
 242
 243 # endif /* No LOAD_AVE_TYPE.  */
 244
 245 # ifdef OSF_ALPHA
 246 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 247    according to ghazi@noc.rutgers.edu.  */
 248 #  undef FSCALE
 249 #  define FSCALE 1024.0
 250 # endif
 251
 252 # if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 253 /* <sys/param.h> defines an incorrect value for FSCALE on an
 254    Alliant FX/2800 Concentrix 2.2, according to ghazi@noc.rutgers.edu.  */
 255 #  undef FSCALE
 256 #  define FSCALE 100.0
 257 # endif
 258
 259
 260 # ifndef        FSCALE
 261
 262 /* SunOS and some others define FSCALE in sys/param.h.  */
 263
 264 #  ifdef MORE_BSD
 265 #   define FSCALE 2048.0
 266 #  endif
 267
 268 #  if defined(MIPS) || defined(SVR4) || defined(decstation)
 269 #   define FSCALE 256
 270 #  endif
 271
 272 #  if defined (sgi) || defined (sequent)
 273 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 274    above under #ifdef MIPS.  But we want the sgi value.  */
 275 #   undef FSCALE
 276 #   define      FSCALE 1000.0
 277 #  endif
 278
 279 #  if defined (ardent) && defined (titan)
 280 #   define FSCALE 65536.0
 281 #  endif
 282
 283 #  ifdef tek4300
 284 #   define FSCALE 100.0
 285 #  endif
 286
 287 #  ifdef _AIX
 288 #   define FSCALE 65536.0
 289 #  endif
 290
 291 # endif /* Not FSCALE.  */
 292
 293 # if !defined (LDAV_CVT) && defined (FSCALE)
 294 #  define       LDAV_CVT(n) (((double) (n)) / FSCALE)
 295 # endif
 296
 297 /* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
 298 # ifndef NLIST_STRUCT
 299
 300 #  ifdef MORE_BSD
 301 #   define NLIST_STRUCT
 302 #  endif
 303
 304 #  ifdef sun
 305 #   define NLIST_STRUCT
 306 #  endif
 307
 308 #  ifdef decstation
 309 #   define NLIST_STRUCT
 310 #  endif
 311
 312 #  ifdef hpux
 313 #   define NLIST_STRUCT
 314 #  endif
 315
 316 #  if defined (_SEQUENT_) || defined (sequent)
 317 #   define NLIST_STRUCT
 318 #  endif
 319
 320 #  ifdef sgi
 321 #   define NLIST_STRUCT
 322 #  endif
 323
 324 #  ifdef SVR4
 325 #   define NLIST_STRUCT
 326 #  endif
 327
 328 #  ifdef sony_news
 329 #   define NLIST_STRUCT
 330 #  endif
 331
 332 #  ifdef OSF_ALPHA
 333 #   define NLIST_STRUCT
 334 #  endif
 335
 336 #  if defined (ardent) && defined (titan)
 337 #   define NLIST_STRUCT
 338 #  endif
 339
 340 #  ifdef tek4300
 341 #   define NLIST_STRUCT
 342 #  endif
 343
 344 #  ifdef butterfly
 345 #   define NLIST_STRUCT
 346 #  endif
 347
 348 #  if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 349 #   define NLIST_STRUCT
 350 #  endif
 351
 352 #  ifdef _AIX
 353 #   define NLIST_STRUCT
 354 #  endif
 355
 356 # endif /* defined (NLIST_STRUCT) */
 357
 358
 359 # if defined(sgi) || (defined(mips) && !defined(BSD))
 360 #  define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 361 # endif
 362
 363
 364 # if !defined (KERNEL_FILE) && defined (sequent)
 365 #  define KERNEL_FILE "/dynix"
 366 # endif
 367
 368 # if !defined (KERNEL_FILE) && defined (hpux)
 369 #  define KERNEL_FILE "/hp-ux"
 370 # endif
 371
 372 # if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || (defined (ardent) && defined (titan)))
 373 #  define KERNEL_FILE "/unix"
 374 # endif
 375
 376
 377 # if !defined (LDAV_SYMBOL) && defined (alliant)
 378 #  define LDAV_SYMBOL "_Loadavg"
 379 # endif
 380
 381 # if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)) || defined (_AIX))
 382 #  define LDAV_SYMBOL "avenrun"
 383 # endif
 384
 385 # ifdef HAVE_UNISTD_H
 386 #  include <unistd.h>
 387 # endif
 388
 389 # include <stdio.h>
 390
 391 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 392    nlist method.  */
 393 # if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
 394 #  define LOAD_AVE_TYPE double
 395 # endif
 396
 397 # ifdef LOAD_AVE_TYPE
 398
 399 #  ifndef VMS
 400 #   ifndef __linux__
 401 #    ifndef NLIST_STRUCT
 402 #     include <a.out.h>
 403 #    else /* NLIST_STRUCT */
 404 #     include <nlist.h>
 405 #    endif /* NLIST_STRUCT */
 406
 407 #    ifdef SUNOS_5
 408 #     include <fcntl.h>
 409 #     include <kvm.h>
 410 #     include <kstat.h>
 411 #    endif
 412
 413 #    if defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 414 #     include <sys/pstat.h>
 415 #    endif
 416
 417 #    ifndef KERNEL_FILE
 418 #     define KERNEL_FILE "/vmunix"
 419 #    endif /* KERNEL_FILE */
 420
 421 #    ifndef LDAV_SYMBOL
 422 #     define LDAV_SYMBOL "_avenrun"
 423 #    endif /* LDAV_SYMBOL */
 424 #   endif /* __linux__ */
 425
 426 #  else /* VMS */
 427
 428 #   ifndef eunice
 429 #    include <iodef.h>
 430 #    include <descrip.h>
 431 #   else /* eunice */
 432 #    include <vms/iodef.h>
 433 #   endif /* eunice */
 434 #  endif /* VMS */
 435
 436 #  ifndef LDAV_CVT
 437 #   define LDAV_CVT(n) ((double) (n))
 438 #  endif /* !LDAV_CVT */
 439
 440 # endif /* LOAD_AVE_TYPE */
 441
 442 # if defined(__GNU__) && !defined (NeXT)
 443 /* Note that NeXT Openstep defines __GNU__ even though it should not.  */
 444 /* GNU system acts much like NeXT, for load average purposes,
 445    but not exactly.  */
 446 #  define NeXT
 447 #  define host_self mach_host_self
 448 # endif
 449
 450 # ifdef NeXT
 451 #  ifdef HAVE_MACH_MACH_H
 452 #   include <mach/mach.h>
 453 #  else
 454 #   include <mach.h>
 455 #  endif
 456 # endif /* NeXT */
 457
 458 # ifdef sgi
 459 #  include <sys/sysmp.h>
 460 # endif /* sgi */
 461
 462 # ifdef UMAX
 463 #  include <stdio.h>
 464 #  include <signal.h>
 465 #  include <sys/time.h>
 466 #  include <sys/wait.h>
 467 #  include <sys/syscall.h>
 468
 469 #  ifdef UMAX_43
 470 #   include <machine/cpu.h>
 471 #   include <inq_stats/statistics.h>
 472 #   include <inq_stats/sysstats.h>
 473 #   include <inq_stats/cpustats.h>
 474 #   include <inq_stats/procstats.h>
 475 #  else /* Not UMAX_43.  */
 476 #   include <sys/sysdefs.h>
 477 #   include <sys/statistics.h>
 478 #   include <sys/sysstats.h>
 479 #   include <sys/cpudefs.h>
 480 #   include <sys/cpustats.h>
 481 #   include <sys/procstats.h>
 482 #  endif /* Not UMAX_43.  */
 483 # endif /* UMAX */
 484
 485 # ifdef DGUX
 486 #  include <sys/dg_sys_info.h>
 487 # endif
 488
 489 # if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 490 #  include <fcntl.h>
 491 # else
 492 #  include <sys/file.h>
 493 # endif
 494 \f
 495 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 496
 497 # ifdef NeXT
 498 static processor_set_t default_set;
 499 static int getloadavg_initialized;
 500 # endif /* NeXT */
 501
 502 # ifdef UMAX
 503 static unsigned int cpus = 0;
 504 static unsigned int samples;
 505 # endif /* UMAX */
 506
 507 # ifdef DGUX
 508 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 509 # endif /* DGUX */
 510
 511 # ifdef LOAD_AVE_TYPE
 512 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 513 static int channel;
 514 /* Nonzero iff channel is valid.  */
 515 static int getloadavg_initialized;
 516 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 517 static long offset;
 518
 519 #  if !defined(VMS) && !defined(sgi) && !defined(__linux__)
 520 static struct nlist nl[2];
 521 #  endif /* Not VMS or sgi */
 522
 523 #  ifdef SUNOS_5
 524 static kvm_t *kd;
 525 #  endif /* SUNOS_5 */
 526
 527 # endif /* LOAD_AVE_TYPE */
 528 \f
 529 /* Put the 1 minute, 5 minute and 15 minute load averages
 530    into the first NELEM elements of LOADAVG.
 531    Return the number written (never more than 3, but may be less than NELEM),
 532    or -1 if an error occurred.  */
 533
 534 int
 535 getloadavg (loadavg, nelem)
 536      double loadavg[];
 537      int nelem;
 538 {
 539   int elem = 0;                 /* Return value.  */
 540
 541 # ifdef NO_GET_LOAD_AVG
 542 #  define LDAV_DONE
 543   /* Set errno to zero to indicate that there was no particular error;
 544      this function just can't work at all on this system.  */
 545   errno = 0;
 546   elem = -1;
 547 # endif
 548
 549 # if !defined (LDAV_DONE) && defined (HAVE_LIBKSTAT)
 550 /* Use libkstat because we don't have to be root.  */
 551 #  define LDAV_DONE
 552   kstat_ctl_t *kc;
 553   kstat_t *ksp;
 554   kstat_named_t *kn;
 555
 556   kc = kstat_open ();
 557   if (kc == 0)
 558     return -1;
 559   ksp = kstat_lookup (kc, "unix", 0, "system_misc");
 560   if (ksp == 0 )
 561     return -1;
 562   if (kstat_read (kc, ksp, 0) == -1)
 563     return -1;
 564
 565
 566   kn = kstat_data_lookup (ksp, "avenrun_1min");
 567   if (kn == 0)
 568     {
 569       /* Return -1 if no load average information is available.  */
 570       nelem = 0;
 571       elem = -1;
 572     }
 573
 574   if (nelem >= 1)
 575     loadavg[elem++] = (double) kn->value.ul/FSCALE;
 576
 577   if (nelem >= 2)
 578     {
 579       kn = kstat_data_lookup (ksp, "avenrun_5min");
 580       if (kn != 0)
 581         {
 582           loadavg[elem++] = (double) kn->value.ul/FSCALE;
 583
 584           if (nelem >= 3)
 585             {
 586               kn = kstat_data_lookup (ksp, "avenrun_15min");
 587               if (kn != 0)
 588                 loadavg[elem++] = (double) kn->value.ul/FSCALE;
 589             }
 590         }
 591     }
 592
 593   kstat_close (kc);
 594 # endif /* HAVE_LIBKSTAT */
 595
 596 # if !defined (LDAV_DONE) && defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 597 /* Use pstat_getdynamic() because we don't have to be root.  */
 598 #  define LDAV_DONE
 599 #  undef LOAD_AVE_TYPE
 600
 601   struct pst_dynamic dyn_info;
 602   if (pstat_getdynamic (&dyn_info, sizeof (dyn_info), 0, 0) < 0)
 603     return -1;
 604   if (nelem > 0)
 605     loadavg[elem++] = dyn_info.psd_avg_1_min;
 606   if (nelem > 1)
 607     loadavg[elem++] = dyn_info.psd_avg_5_min;
 608   if (nelem > 2)
 609     loadavg[elem++] = dyn_info.psd_avg_15_min;
 610
 611 # endif /* hpux && HAVE_PSTAT_GETDYNAMIC */
 612
 613 # if !defined (LDAV_DONE) && defined (__linux__)
 614 #  define LDAV_DONE
 615 #  undef LOAD_AVE_TYPE
 616
 617 #  ifndef LINUX_LDAV_FILE
 618 #   define LINUX_LDAV_FILE "/proc/loadavg"
 619 #  endif
 620
 621   char ldavgbuf[40];
 622   double load_ave[3];
 623   int fd, count;
 624
 625   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 626   if (fd == -1)
 627     return -1;
 628   count = read (fd, ldavgbuf, 40);
 629   (void) close (fd);
 630   if (count <= 0)
 631     return -1;
 632
 633   count = sscanf (ldavgbuf, "%lf %lf %lf",
 634                   &load_ave[0], &load_ave[1], &load_ave[2]);
 635   if (count < 1)
 636     return -1;
 637
 638   for (elem = 0; elem < nelem && elem < count; elem++)
 639     loadavg[elem] = load_ave[elem];
 640
 641   return elem;
 642
 643 # endif /* __linux__ */
 644
 645 # if !defined (LDAV_DONE) && defined (__NetBSD__)
 646 #  define LDAV_DONE
 647 #  undef LOAD_AVE_TYPE
 648
 649 #  ifndef NETBSD_LDAV_FILE
 650 #   define NETBSD_LDAV_FILE "/kern/loadavg"
 651 #  endif
 652
 653   unsigned long int load_ave[3], scale;
 654   int count;
 655   FILE *fp;
 656
 657   fp = fopen (NETBSD_LDAV_FILE, "r");
 658   if (fp == NULL)
 659     return -1;
 660   count = fscanf (fp, "%lu %lu %lu %lu\n",
 661                   &load_ave[0], &load_ave[1], &load_ave[2],
 662                   &scale);
 663   (void) fclose (fp);
 664   if (count != 4)
 665     return -1;
 666
 667   for (elem = 0; elem < nelem; elem++)
 668     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 669
 670   return elem;
 671
 672 # endif /* __NetBSD__ */
 673
 674 # if !defined (LDAV_DONE) && defined (NeXT)
 675 #  define LDAV_DONE
 676   /* The NeXT code was adapted from iscreen 3.2.  */
 677
 678   host_t host;
 679   struct processor_set_basic_info info;
 680   unsigned info_count;
 681
 682   /* We only know how to get the 1-minute average for this system,
 683      so even if the caller asks for more than 1, we only return 1.  */
 684
 685   if (!getloadavg_initialized)
 686     {
 687       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 688         getloadavg_initialized = 1;
 689     }
 690
 691   if (getloadavg_initialized)
 692     {
 693       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 694       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 695                               (processor_set_info_t) &info, &info_count)
 696           != KERN_SUCCESS)
 697         getloadavg_initialized = 0;
 698       else
 699         {
 700           if (nelem > 0)
 701             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 702         }
 703     }
 704
 705   if (!getloadavg_initialized)
 706     return -1;
 707 # endif /* NeXT */
 708
 709 # if !defined (LDAV_DONE) && defined (UMAX)
 710 #  define LDAV_DONE
 711 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 712    have a /dev/kmem.  Information about the workings of the running kernel
 713    can be gathered with inq_stats system calls.
 714    We only know how to get the 1-minute average for this system.  */
 715
 716   struct proc_summary proc_sum_data;
 717   struct stat_descr proc_info;
 718   double load;
 719   register unsigned int i, j;
 720
 721   if (cpus == 0)
 722     {
 723       register unsigned int c, i;
 724       struct cpu_config conf;
 725       struct stat_descr desc;
 726
 727       desc.sd_next = 0;
 728       desc.sd_subsys = SUBSYS_CPU;
 729       desc.sd_type = CPUTYPE_CONFIG;
 730       desc.sd_addr = (char *) &conf;
 731       desc.sd_size = sizeof conf;
 732
 733       if (inq_stats (1, &desc))
 734         return -1;
 735
 736       c = 0;
 737       for (i = 0; i < conf.config_maxclass; ++i)
 738         {
 739           struct class_stats stats;
 740           bzero ((char *) &stats, sizeof stats);
 741
 742           desc.sd_type = CPUTYPE_CLASS;
 743           desc.sd_objid = i;
 744           desc.sd_addr = (char *) &stats;
 745           desc.sd_size = sizeof stats;
 746
 747           if (inq_stats (1, &desc))
 748             return -1;
 749
 750           c += stats.class_numcpus;
 751         }
 752       cpus = c;
 753       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 754     }
 755
 756   proc_info.sd_next = 0;
 757   proc_info.sd_subsys = SUBSYS_PROC;
 758   proc_info.sd_type = PROCTYPE_SUMMARY;
 759   proc_info.sd_addr = (char *) &proc_sum_data;
 760   proc_info.sd_size = sizeof (struct proc_summary);
 761   proc_info.sd_sizeused = 0;
 762
 763   if (inq_stats (1, &proc_info) != 0)
 764     return -1;
 765
 766   load = proc_sum_data.ps_nrunnable;
 767   j = 0;
 768   for (i = samples - 1; i > 0; --i)
 769     {
 770       load += proc_sum_data.ps_nrun[j];
 771       if (j++ == PS_NRUNSIZE)
 772         j = 0;
 773     }
 774
 775   if (nelem > 0)
 776     loadavg[elem++] = load / samples / cpus;
 777 # endif /* UMAX */
 778
 779 # if !defined (LDAV_DONE) && defined (DGUX)
 780 #  define LDAV_DONE
 781   /* This call can return -1 for an error, but with good args
 782      it's not supposed to fail.  The first argument is for no
 783      apparent reason of type `long int *'.  */
 784   dg_sys_info ((long int *) &load_info,
 785                DG_SYS_INFO_LOAD_INFO_TYPE,
 786                DG_SYS_INFO_LOAD_VERSION_0);
 787
 788   if (nelem > 0)
 789     loadavg[elem++] = load_info.one_minute;
 790   if (nelem > 1)
 791     loadavg[elem++] = load_info.five_minute;
 792   if (nelem > 2)
 793     loadavg[elem++] = load_info.fifteen_minute;
 794 # endif /* DGUX */
 795
 796 # if !defined (LDAV_DONE) && defined (apollo)
 797 #  define LDAV_DONE
 798 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 799
 800    This system call is not documented.  The load average is obtained as
 801    three long integers, for the load average over the past minute,
 802    five minutes, and fifteen minutes.  Each value is a scaled integer,
 803    with 16 bits of integer part and 16 bits of fraction part.
 804
 805    I'm not sure which operating system first supported this system call,
 806    but I know that SR10.2 supports it.  */
 807
 808   extern void proc1_$get_loadav ();
 809   unsigned long load_ave[3];
 810
 811   proc1_$get_loadav (load_ave);
 812
 813   if (nelem > 0)
 814     loadavg[elem++] = load_ave[0] / 65536.0;
 815   if (nelem > 1)
 816     loadavg[elem++] = load_ave[1] / 65536.0;
 817   if (nelem > 2)
 818     loadavg[elem++] = load_ave[2] / 65536.0;
 819 # endif /* apollo */
 820
 821 # if !defined (LDAV_DONE) && defined (OSF_MIPS)
 822 #  define LDAV_DONE
 823
 824   struct tbl_loadavg load_ave;
 825   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 826   loadavg[elem++]
 827     = (load_ave.tl_lscale == 0
 828        ? load_ave.tl_avenrun.d[0]
 829        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 830 # endif /* OSF_MIPS */
 831
 832 # if !defined (LDAV_DONE) && (defined (__MSDOS__) || defined (WINDOWS32))
 833 #  define LDAV_DONE
 834
 835   /* A faithful emulation is going to have to be saved for a rainy day.  */
 836   for ( ; elem < nelem; elem++)
 837     {
 838       loadavg[elem] = 0.0;
 839     }
 840 # endif  /* __MSDOS__ || WINDOWS32 */
 841
 842 # if !defined (LDAV_DONE) && defined (OSF_ALPHA)
 843 #  define LDAV_DONE
 844
 845   struct tbl_loadavg load_ave;
 846   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 847   for (elem = 0; elem < nelem; elem++)
 848     loadavg[elem]
 849       = (load_ave.tl_lscale == 0
 850        ? load_ave.tl_avenrun.d[elem]
 851        : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
 852 # endif /* OSF_ALPHA */
 853
 854 # if !defined (LDAV_DONE) && defined (VMS)
 855   /* VMS specific code -- read from the Load Ave driver.  */
 856
 857   LOAD_AVE_TYPE load_ave[3];
 858   static int getloadavg_initialized = 0;
 859 #  ifdef eunice
 860   struct
 861   {
 862     int dsc$w_length;
 863     char *dsc$a_pointer;
 864   } descriptor;
 865 #  endif
 866
 867   /* Ensure that there is a channel open to the load ave device.  */
 868   if (!getloadavg_initialized)
 869     {
 870       /* Attempt to open the channel.  */
 871 #  ifdef eunice
 872       descriptor.dsc$w_length = 18;
 873       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 874 #  else
 875       $DESCRIPTOR (descriptor, "LAV0:");
 876 #  endif
 877       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 878         getloadavg_initialized = 1;
 879     }
 880
 881   /* Read the load average vector.  */
 882   if (getloadavg_initialized
 883       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 884                      load_ave, 12, 0, 0, 0, 0) & 1))
 885     {
 886       sys$dassgn (channel);
 887       getloadavg_initialized = 0;
 888     }
 889
 890   if (!getloadavg_initialized)
 891     return -1;
 892 # endif /* VMS */
 893
 894 # if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 895
 896   /* UNIX-specific code -- read the average from /dev/kmem.  */
 897
 898 #  define LDAV_PRIVILEGED               /* This code requires special installation.  */
 899
 900   LOAD_AVE_TYPE load_ave[3];
 901
 902   /* Get the address of LDAV_SYMBOL.  */
 903   if (offset == 0)
 904     {
 905 #  ifndef sgi
 906 #   ifndef NLIST_STRUCT
 907       strcpy (nl[0].n_name, LDAV_SYMBOL);
 908       strcpy (nl[1].n_name, "");
 909 #   else /* NLIST_STRUCT */
 910 #    ifdef NLIST_NAME_UNION
 911       nl[0].n_un.n_name = LDAV_SYMBOL;
 912       nl[1].n_un.n_name = 0;
 913 #    else /* not NLIST_NAME_UNION */
 914       nl[0].n_name = LDAV_SYMBOL;
 915       nl[1].n_name = 0;
 916 #    endif /* not NLIST_NAME_UNION */
 917 #   endif /* NLIST_STRUCT */
 918
 919 #   ifndef SUNOS_5
 920       if (
 921 #    if !(defined (_AIX) && !defined (ps2))
 922           nlist (KERNEL_FILE, nl)
 923 #    else  /* _AIX */
 924           knlist (nl, 1, sizeof (nl[0]))
 925 #    endif
 926           >= 0)
 927           /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 928           {
 929 #    ifdef FIXUP_KERNEL_SYMBOL_ADDR
 930             FIXUP_KERNEL_SYMBOL_ADDR (nl);
 931 #    endif
 932             offset = nl[0].n_value;
 933           }
 934 #   endif /* !SUNOS_5 */
 935 #  else  /* sgi */
 936       int ldav_off;
 937
 938       ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 939       if (ldav_off != -1)
 940         offset = (long) ldav_off & 0x7fffffff;
 941 #  endif /* sgi */
 942     }
 943
 944   /* Make sure we have /dev/kmem open.  */
 945   if (!getloadavg_initialized)
 946     {
 947 #  ifndef SUNOS_5
 948       channel = open ("/dev/kmem", 0);
 949       if (channel >= 0)
 950         {
 951           /* Set the channel to close on exec, so it does not
 952              litter any child's descriptor table.  */
 953 #   ifdef FD_SETFD
 954 #    ifndef FD_CLOEXEC
 955 #     define FD_CLOEXEC 1
 956 #    endif
 957           (void) fcntl (channel, F_SETFD, FD_CLOEXEC);
 958 #   endif
 959           getloadavg_initialized = 1;
 960         }
 961 #  else /* SUNOS_5 */
 962       /* We pass 0 for the kernel, corefile, and swapfile names
 963          to use the currently running kernel.  */
 964       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 965       if (kd != 0)
 966         {
 967           /* nlist the currently running kernel.  */
 968           kvm_nlist (kd, nl);
 969           offset = nl[0].n_value;
 970           getloadavg_initialized = 1;
 971         }
 972 #  endif /* SUNOS_5 */
 973     }
 974
 975   /* If we can, get the load average values.  */
 976   if (offset && getloadavg_initialized)
 977     {
 978       /* Try to read the load.  */
 979 #  ifndef SUNOS_5
 980       if (lseek (channel, offset, 0) == -1L
 981           || read (channel, (char *) load_ave, sizeof (load_ave))
 982           != sizeof (load_ave))
 983         {
 984           close (channel);
 985           getloadavg_initialized = 0;
 986         }
 987 #  else  /* SUNOS_5 */
 988       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 989           != sizeof (load_ave))
 990         {
 991           kvm_close (kd);
 992           getloadavg_initialized = 0;
 993         }
 994 #  endif /* SUNOS_5 */
 995     }
 996
 997   if (offset == 0 || !getloadavg_initialized)
 998     return -1;
 999 # endif /* LOAD_AVE_TYPE and not VMS */
1000
1001 # if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
1002   if (nelem > 0)
1003     loadavg[elem++] = LDAV_CVT (load_ave[0]);
1004   if (nelem > 1)
1005     loadavg[elem++] = LDAV_CVT (load_ave[1]);
1006   if (nelem > 2)
1007     loadavg[elem++] = LDAV_CVT (load_ave[2]);
1008
1009 #  define LDAV_DONE
1010 # endif /* !LDAV_DONE && LOAD_AVE_TYPE */
1011
1012 # ifdef LDAV_DONE
1013   return elem;
1014 # else
1015   /* Set errno to zero to indicate that there was no particular error;
1016      this function just can't work at all on this system.  */
1017   errno = 0;
1018   return -1;
1019 # endif
1020 }
1021
1022 #endif /* ! HAVE_GETLOADAVG */
1023 \f
1024 #ifdef TEST
1025 void
1026 main (argc, argv)
1027      int argc;
1028      char **argv;
1029 {
1030   int naptime = 0;
1031
1032   if (argc > 1)
1033     naptime = atoi (argv[1]);
1034
1035   while (1)
1036     {
1037       double avg[3];
1038       int loads;
1039
1040       errno = 0;                /* Don't be misled if it doesn't set errno.  */
1041       loads = getloadavg (avg, 3);
1042       if (loads == -1)
1043         {
1044           perror ("Error getting load average");
1045           exit (1);
1046         }
1047       if (loads > 0)
1048         printf ("1-minute: %f  ", avg[0]);
1049       if (loads > 1)
1050         printf ("5-minute: %f  ", avg[1]);
1051       if (loads > 2)
1052         printf ("15-minute: %f  ", avg[2]);
1053       if (loads > 0)
1054         putchar ('\n');
1055
1056       if (naptime == 0)
1057         break;
1058       sleep (naptime);
1059     }
1060
1061   exit (0);
1062 }
1063 #endif /* TEST */